(Adds Oil Search-Santos, removes Altium-Autodesk) July 15...

(Adds Oil Search-Santos, removes Altium-Autodesk)

July 15 (Reuters) - Australia is seeing a flurry of deal-making so far this year, as record-low interest rates have given institutional investors and companies a well-funded war chest to chase higher valuations.

From potentially one of Australia's biggest-ever buyouts to a multi-party tussle for a troubled casino giant, here are some of the major deals Down Under in 2021:

Vocus Group - Macquarie/Aware Super Vocus Group (VOC) in March agreed to a A$3.5 billion ($2.61 billion) takeover offer from a consortium of a Macquarie (MQG) fund and pension fund Aware Super.

Orocobre - Galaxy Resources Orocobre Ltd (ORE) in April agreed to buy Galaxy Resources (GXY) for $1.4 billion to create the world's fifth most valuable lithium producer.

BINGO Industries - Macquarie Waste management firm BINGO Industries (BIN) in April agreed to a A$2.3 billion ($1.72 billion) buyout offer from funds managed by Macquarie (MQG) .

Tilt Renewables - PowAR/Mercury NZ New Zealand-listed Tilt Renewables (TLT) in April agreed to a NZ$3.07 billion ($2.15 billion) bid from a consortium including AGL Energy (AGL) , Australia's sovereign wealth fund, and Mercury NZ (MCY) .

Tabcorp - Entain/Apollo Global/Betmakers UK's Entain ENT.L in February offered to buy betting firm Tabcorp Holdings' (TAH) wagering and media business. In April, it sweetened its offer to A$3.5 billion ($2.61 billion).

In May, Apollo Global Management APO.N matched Entain's offer, and BetMakers Technology (BET) jumped in with a A$4 billion ($2.98 billion) bid.

Crown Resorts - Blackstone/Star Entertainment Casino giant Crown Resorts (CWN) in March received a A$8 billion ($5.97 billion) buyout proposal from Blackstone BX.N and a A$9 billion ($6.71 billion) all-stock offer from peer Star Entertainment Group (SGR) in May.

Oaktree Capital Group OAK_pa.N is also in the race for Crown.

Washington H Soul Pattinson - Milton Corp Australia's Washington H Soul Pattinson (SOL) said in June it will buy Milton Corp (MLT) in a deal that values the target at A$4.05 billion ($3.02 billion).

Ramsay Health Care - Spire Healthcare Hospital operator Ramsay Health Care (RHC) said in May it would buy British peer Spire Healthcare SPI.L for 1 billion pounds ($1.38 billion).

In July, Ramsay sweetened its bid to 1.04 billion pounds ($1.44 billion).

Boral - Seven Group In May, diversified investor Seven Group (SVW) offered to buy shares it does not already own in Boral (BLD) , valuing the building materials supplier at $6.23 billion.

In July, Seven raised its offer to A$8.75 billion ($6.53 billion), which was rejected.

National Australia Bank - Citigroup National Australia Bank (NAB) , the country's third-largest lender, said in July it was in talks with Citigroup C.N to buy the U.S. bank's Australian consumer business.

Sydney Airport - Sydney Aviation Alliance A consortium called Sydney Aviation Alliance in July made a A$22.26 billion ($16.61 billion) play for Sydney Airport Holdings (SYD) . If the deal goes through, it will be one of the biggest ever in Australia.

Spark Infrastructure - KKR/Ontario Teachers' Pension Plan Board

In July, Spark Infrastructure (SKI) received a A$4.91 billion ($3.67 billion) takeover bid from a consortium including KKR KKR.N and Canada's Ontario Teachers' Pension Plan Board.

Oil Search - Santos Papua New Guinea-focused oil and gas producer Oil Search (OSH) in July rejected Santos Ltd's (STO) A$8.80 billion ($6.5 billion) bid, but said it was open to revised offer.